A. Field of the Invention
This invention relates to a device for holding capsules during immersion testing and, in particular, to a capsule holder wherein the capsule is loosely held by resilient fingers.
B. Background Art
In pharmaceutical and laboratory research, capsules (usually containing pharmaceutical agents) are immersed in acid solutions which simulate stomach acid to determine the dissolution characteristics of the capsule when the capsule is exposed to stomach acid. Therefore a capsule undergoing dissolution testing is retained in a device which permits fluid to freely flow to the capsule while having minimum surface contact with the capsule. The capsule holding device is preferably formed of a material which is not easily corrodible by the acid. For efficient testing of a large number of capsules, insertion of a capsule into the capsule holder should be easily performed.
For this type of immersion testing, it is known in the art to entrap capsules, for example, in a gold coated or stainless steel wire basket or in a few turns of non-corrosive wire. Nevertheless, the material holding the capsule usually corrodes over a period of time due to exposure to the acids.
It is also known generally to grip objects with devices having claws or fingers. See, for example U.S. Pat. No. 559,840--Bromley and U.S. Pat. No. 1,545,693--Phoel. Bromley discloses a plurality of pivoted jaws for retaining and handling a small object. However the handle of Bromley's tool must be rotated to open and close the jaws thereby preventing convenient insertion of the object into the tool. The tool disclosed by Phoel also may be used to grasp a small object. However the grasping device taught by Phoel grasps the object tightly and would not be suitable for immersion testing of capsules in which the capsule may be deformed or ruptured by a tightly grasping holding device thereby possible distorting dissolution resolution data.
U.S. Pat. No. 3,888,362--Fletcher et al., U.S. Pat. No. 4,260,187--Bejczy, and U.S. Pat. No. 649,785--Weinert also teach devices for grasping an object in which inconvenient mechanical manipulation is required for opening the grasping device and the jaws of the grasping device may press tightly upon the object grasped. Other patents identified to be of possible interest in a brief patentability search which was conducted for purposes of considering the patentability of the invention disclosed and claimed herein were:
U.S. Pat. No. 2,102,546: Schatz PA1 U.S. Pat. No. 2,416,109: Terry PA1 U.S. Pat. No. 2,827,689: Shoffner et al. PA1 U.S. Pat. No. 3,113,799: Budnik PA1 U.S. Pat. No. 3,640,519: Halstead PA1 U.S. Pat. No. 3,696,490: Secunda PA1 U.S. Pat. No. 4,439,090: Schaefer
Applicant believes these patents are no more pertinent to the present invention than those discussed specifically above.